export default {
	// 为当前模块开启命名空间
	namespaced: true,

	// 模块的 state 数据
	state: () => ({
		// 购物车的数组，用来存储购物车中每个商品的信息对象
		// 每个商品的信息对象，都包含如下 6 个属性：
		// { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
		cart: JSON.parse(uni.getStorageSync('cart') || '[]'),
	}),

	// 模块的 mutations 方法
	mutations: {

		// 添加购物车商品数据
		addToCart(state, goods) {
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id);
			if (!findResult) {
				state.cart = [...state.cart, goods]
			} else {
				findResult.goods_count++
			};
			this.commit('m_cart/saveToStorage')
		},

		// 购物车数据持久化
		saveToStorage(state) {
			uni.setStorageSync('cart', JSON.stringify(state.cart))
		},

		// 更新购物车中商品的勾选状态
		updateGoodsState(state, goods) {
			// 根据 goods_id 查询购物车中对应商品的信息对象
			// const findResult = state.cart.find(x => x.goods_id == goods.goods_id);
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
			// 有对应的商品信息对象
			if (findResult) {
				findResult.goods_state = goods.goods_state;
				this.commit('m_cart/saveToStorage')
			}
		},

		// 更新购物车中商品的数量
		updateGoodsCount(state, goods) {
			// 根据 goods_id 查询购物车中对应商品的信息对象
			// const findResult = state.cart.find(x => x.goods_id == goods.goods_id);
			const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
			// 有对应的商品信息对象
			if (findResult) {
				findResult.goods_count = goods.goods_count;
				this.commit('m_cart/saveToStorage')
			}
		},

		// 根据 ID 从购物车中删除对应的商品信息
		removeGoodsById(state, goods_id) {
			// 调用数组的 filter 方法进行过滤
			state.cart = state.cart.filter(x => x.goods_id !== goods_id);
			this.commit('m_cart/saveToStorage')
		},

		// 更新所有商品的勾选状态
		updateAllGoodsState(state, newState) {
			state.cart.forEach(x => x.goods_state = newState);
			this.commit('m_cart/saveToStorage')
		}
	},

	// 模块的 getters 属性
	getters: {
		total(state) {
			// let count = 0;
			// state.cart.forEach(x => count += x.goods_count);
			// return count;
			return state.cart.reduce((total, item) => total += item.goods_count, 0)
		},

		// 购物车勾选的商品总数量
		checkedCount(state) {
			return state.cart.filter(x => x.goods_state).reduce((total, item) => {
				return total += item.goods_count
			}, 0)
		},

		// 已勾选的商品的总价
		checkedGoodsAmount(state) {
			return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count * item
				.goods_price, 0).toFixed(2)
		}
	},

	// 
	action: {}
}
